Tree level Leptogenesis from Kalb-Ramond Torsion Background
Abstract
The effect of torsion in theories of quantum gravity is known to be well described by an axion-like field which couples to matter as well as to gravitation and radiation gauge fields. In this note we consider a particular kind of torsion, arising from the Kalb-Ramond antisymmetric tensor field that appears in the gravitational multiplet of string theory. We investigate the implications for leptogenesis. It is shown that leptogenesis can occur even at tree-level and with only one generation of right-handed Majorana neutrinos, due to CP and CPT violation introduced by the background geometry.
Cite
@article{arxiv.1412.7077,
title = {Tree level Leptogenesis from Kalb-Ramond Torsion Background},
author = {M. de Cesare and Nick E. Mavromatos and Sarben Sarkar},
journal= {arXiv preprint arXiv:1412.7077},
year = {2015}
}
Comments
24 pages, rev tex, two pdf figures incorporated; clarifying remarks added in sections IIA,B on the nature of the string-inspired solution with Kalb-Ramond torsion, as well as in section VA, on the thermal evolution of the torsion after decoupling of right-handed Majorana fermions. No effect on conclusions. Some references were also added